A large field of GOP presidential contenders debated each other at Iowa State University in Ames, IA. From left, Rick Santorum, Herman Cain, Ron Paul, Mitt Romney, Michele Bachmann, Tim Pawlenty,Jon Huntsman and Newt Gingrich.

On All Things Considered, NPR's Don Gonyea prepares for tonight's Republican presidential debate — by some counts the 19th of the campaign season — by taking a quick look back at debate highlights, and some lowlights, so far.

From its earliest days last summer, the 2012 campaign has defied prediction. Three states have voted so far, producing three different winners in the early battle for the GOP presidential nomination.

Gonyea notes that this cycle, one factor does stand above all others in driving the dynamics of the race for the GOP nomination — televised debates.

Tonight's debate in Florida is the last before that state's Jan. 31 primary. NPR's Mark Memmott will be live blogging the debate here.

Copyright 2017 NPR. To see more, visit http://www.npr.org/.

MELISSA BLOCK, HOST:

From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.

ROBERT SIEGEL, HOST:

And I'm Robert Siegel. From its earliest days, the 2012 presidential race has defied prediction. Three states have voted so far in this primary season, producing three different winners. One factor stands above all others in driving the dynamics of the race for the GOP nomination, televised debates and there's another one tonight in Florida. NPR national political correspondent Don Gonyea has this look at the impact the debates have had and their unprecedented popularity.

DON GONYEA, BYLINE: First off, it seems inadequate to describe them simply as debates. They've actually been more like regular installments of a blockbuster TV series.

(SOUNDBITE OF PRESIDENTIAL DEBATE)

GONYEA: There's been a mix of familiar characters, names like Romney and Gingrich and the introduction of new political stars including Congresswoman and Tea Party favorite, Michele Bachmann, who actually used a candidate's debate to announce her candidacy in June.

REPRESENTATIVE MICHELE BACHMANN: I filed, today, my paperwork to seek the office of the presidency of the United States today.

GONYEA: Bachmann did well in that debate. She surged in polls. For another candidate, though, former Minnesota Governor Tim Pawlenty, the same event brought trouble. He had been publically attacking Mitt Romney and his Massachusetts health care law using the term Obamney-care, a catchy line, but Pawlenty wouldn't use it in the debate, prompting this from CNN's John King.

JOHN KING: If it was Obamney-care on Fox News Sunday, why is it not Obamney-care standing here with the governor right there?

TIM PAWLENTY: It is. President Obama is the person who I quoted in saying he looked to Massachusetts for designing his program. He's the one who said...

GONYEA: Pawlenty offered a long explanation, but in an instant, he was labeled not tough enough. He never recovered. There were others more than ready to grab the spotlight.

GONYEA: Thanks to the debates, Cain, too, rose to the top in polls, even with little time spent in Iowa and New Hampshire. Voters have clearly been paying attention. Andy Kohut of the Pew Research Center notes that in December, four years ago, one-third of likely GOP primary voters said they'd watched one or more debates.

ANDY KOHUT: In January of 2012, that percentage is 47 percent, a very, very big increase.

GONYEA: One big reason is that GOP voters this year are enthusiastic about the election, that they're hungry for information about the candidates. But Kohut also says the debates themselves have delivered the goods.

KOHUT: Virtually all of the important moments in this campaign have occurred on these debate stages.

GONYEA: Just ask Texas Governor Rick Perry, who entered the race as an instant frontrunner, but seemed unprepared in debates, hitting the low point of his entire campaign in November.

GOVERNOR RICK PERRY: The third agency of government I would do away with - education, the commerce and let's see, I can't - the third one, I can't. I'm sorry. Oops.

GONYEA: Perry never recovered, but he did stay in the race and weeks later, forced his multimillionaire rival, Mitt Romney, into an awkward moment of his own. The topic, again, was health care.

GONYEA: That moment and Romney's more recent handling of the issue of his tax returns have put him on the defensive. Early on, the debate stage was so crowded, some candidates complained they barely got a chance to talk. Senator Rick Santorum grumbled about that back in November.

RICK SANTORUM: Hold on. I'm not done yet.

UNIDENTIFIED MAN 1: Thank you.

SANTORUM: I'm not done yet. I've only been able to answer one question, unlike everybody else here, so let me just finish what I'm saying.

UNIDENTIFIED MAN 1: Okay.

SANTORUM: We need to repeal Obama-care...

GONYEA: Getting noticed hasn't been a problem for Congressman Ron Paul, though often it's because he's so far from the rest of the field on issues, such as defense policy and national security. Last week, he criticized the killing of Osama bin Laden.

RON PAUL: Just think, Adolf Eichmann was captured. He was given a trial. What's wrong with capturing people? Why didn't we try to get some information from him? You know, we're accustomed to asking people questions...

GONYEA: The audience reaction...

(SOUNDBITE OF AUDIENCE BOOING)

GONYEA: Debate audiences have been another character in the drama, cheering or jeering answers and questions. No candidate has taken advantage of that like Newt Gingrich. A classic example came in South Carolina last week. The moderator asked about a claim by one of Gingrich's ex-wives that he wanted an open marriage.

UNIDENTIFIED MAN 3: Would you like to take some time to respond to that?

NEWT GINGRICH: No. But I will.

GONYEA: Then, came this.

GINGRICH: I think the destructive, vicious, negative nature of much of the news media makes it harder to govern this country, harder to attract decent people to run for public office and I am appalled that you would begin a presidential debate on a topic like that.

GONYEA: In that single moment, Gingrich carried the day. Forty-eight hours later, he won the South Carolina primary. He had the debate and the opportunity it created to thank.